Machine type communication (MTC) refers to network communication between one or more network elements or devices without requiring human interaction, or may be referred to as machine-to-machine (M2M) communication. The MTC and some other MTC-like communications have features such as light interaction traffic and interaction burst. Therefore, data transmission in processes of the MTC and other MTC-like communication is generally referred to as small data transmission or low data usage transmission. Correspondingly, compared with a human-to-human (H2H) terminal, an MTC terminal and a terminal similar to the MTC terminal are generally referred to as small data transmission terminals or low data usage terminals.
At present, various types of small data transmission are implemented by combining a small data transmission architecture and a mobile communications network. Small data transmission in MTC is used as an example. An MTC architecture mainly includes an MTC-Interworking Function (MTC-IWF) network element and a service capability server (SCS). The MTC-IWF mainly implements functions such as SCS authentication, external identifier mapping, and make inquiry of a home subscriber server (HSS) in a mobile communications network to obtain service node information. The SCS provides a capability of MTC application, for example, a service capability such as M2M terminal triggering. However, the MTC application is provided by an application server (AS) outside the MTC architecture. To ensure small data transmission, in an existing solution, a network element, such as a packet data network gateway (PGW), in a mobile communications network needs to allocate an Internet Protocol (IP) address to each small data transmission terminal, create a radio access bearer (RAB) corresponding to data transmission, and reserve a resource required for data transmission, which causes waste of a resource in the mobile communications network.